Objective: The burden of clinically relevant noncoronary atherosclerotic occlusive disease in patients with abdominal aortic aneurysms (AAAs) is poorly defined. Furthermore, the cost-effectiveness of routine versus selective preoperative noninvasive examination of the carotid and lower extremity arterial beds has not been established in patients who undergo elective AAA repair.
Methods: Diagnostic vascular laboratory study results were reviewed in 206 patients who underwent evaluation before AAA repair from 1994 to 1998. The patients underwent routine preoperative carotid duplex scan examinations and lower extremity Doppler scan arterial studies with ankle-brachial index (ABI) determinations. The medical records were reviewed for the identification of clinical evidence consistent with cerebrovascular or lower extremity arterial occlusive disease. The costs of routine screening and selective screening were determined with Medicare reimbursement schedules.
Results: The prevalence rate of advanced (80% to 100%) carotid artery stenosis (CAS) was 3.4%, and 18% of the patients had CAS between 60% and 100%. Advanced peripheral vascular occlusive disease (PVOD; ABI, <0.3) was found in 3% of the patients, and 12% of the patients had an ABI of less than 0.6. Most patients with advanced CAS (71%) or advanced PVOD (83%) had clinical indications of their disease. The absence of clinical evidence of disease had a negative predictive value of 99% for both advanced CAS and PVOD. The cost of routine screening for all patients for advanced CAS was $5445 per case. Routine screening for severe PVOD costs were $3732 per case discovered. In contrast, the costs for selective screening for advanced CAS or PVOD in patients with appropriate history or symptoms were $1258 and $785 per case found, respectively.
Conclusion: Routine noninvasive diagnostic testing for the identification of asymptomatic CAS and PVOD in patients with AAA may not be justified. Preoperative screening is more clearly indicated for patients with AAAs who have clinical evidence suggestive of CAS or PVOD.